Tilt compensator for typewriters



Dec. 5, 1950 H. G. HARTMAN TILT COMPENSATOR FOR TYPEWRITERS Filed Dec.12, 1947 JNVENTOR. HER/MAN a HART/MAN ATTORNEY UNITED STATES PATENTOFFICE.

TILT 'QOMPENSATOR FOR; TYPEWRITERS Herman G, Hartman, Rockville, Md-.,assig-nor:to

. Underwood Corporation, New YorlnN. Y'., a,

corporation of. Delaware Application'Decembcr 12, 1941', Serial No.731,290

3. Claims.

This application relates to an improvement in paper carriages fortypewriters. and isaparticu larly directedto a counterbalancing meansfor such carriages. Such counterbalancing is: highly desirable when thetypewriter isv subjected. to) var:- iable degrees of tilting as onboardash-ipor other unsteady" object;

When a. conventional typewriter is being used on a; ship, it can nothe'continuously operated for when, due tothe: roll. or pitch. oithe.ship,- the 10- line: 3-3 of Figure 1.

machine. is tiltedup on the left: hand. side, the Generally tinventi-(mv comprise an, tt component; of the carri'age-weight which isdi-- ment for therear of a-typewriterhavinga guide rected al'ongthelineof motion of the carriage rail or rails for the support of acounterweight will; at some angle, equal; the force; of the-cansubstantially equal in weight to the weight: of riagevfeeding Sp therewill beino carriage 15' the papercarriage. The counter-weight; is free.

escapement. in: response cooperation; ofi a type keyx. This-will:result: letters lacing-typed one on; top. of the other and an:illegible: result with a. slightly-greater-tilt, such" component of:the.

carriage weight: will be; so: large: asv to: overcome the tension. ofthe: carriage feeding: spring: and

the carriage will be involuntarily returned to the;

right; When; the; tilt; is in. the.- oppositedi-rection.this;.component: of: the carriage weight willchezn:

against. the. es'capementcdogs resulting. in a. jam;-

ming: of: the. escapement or: a possible skipping. with double or: more..l'etterieed.

The roll of ashipis; accentuated by'badiweather or high speed. such.that: use of a. conventionaltypewriter is possible only intermittently.Such conditions, howevenincreasethe'dutiessoi 8.'18J(1lf0j operatorwhose messa es must he recorded and who has heretofore: been forcedto:resort. to. man ual 'transcriptioni at a rate considerably.slowerthan-normal.

It is therefore; an object of the; present. invention to provide atypewriter in whichnthe can riage i's. unaiiectedby any reasonablyexpected" tilt of the typewriter frame.

It is also anobj'ect toprovide atypewri'tercar'- ri'age compensatedfor-- lateral tilting-of a type writer.

A further object is to provide a counterbalance for a typewritercarriage, such device being efiective at all positions of the carriageand for either direction of tilt of the machine frame.

It. is also an object of the present invention to compensate atypewriter carriage for the. effiect.

2, Other objects of the invention will be apparent from thespecification and claims which follow.

in thedrawi-ngs- Figure 1 is atop View of the rear portionvafatypewriter showing the improvement attached.

thereto,

Figure 2 is a side view ofa: rear portion: of the. machine, and

Figure 3 is a sectional side view taken alongtlie.

to move on the guide rails: and is attached-to thecarriage by a motionreversing drivei such manner that the weightiis moved by the. carriage"in a direction opposite to thedi'rection of car- 7 ri'age movement.

When the typewriter is:tilted' to;-an-:.uneyen position, the componentcf: the; carriage weight. which is acting along the guide railslwilldepending upon the direction of tilting, either augment, or oppose theforce of the carriage feeding spring. and thus change the pressure ofthe carriage. on

the escapement mecl'lanisxrr.v At certain degrees of tilt the combinedforces arelsuch that-the: escapement will not operate and the carriagewill not escape in responseto an operation of a typekey. Thecounterweightwill' be similarly affected by the tiltingof the typewriterbase. and the: com;- ponent of force tending to. move the: counterweightalong the guicle rail is su' tantiall'y equal to'that tending to changetheeffiec-tive: force of More specifically, the-invention is inthe ac--companying' drawings" shown as applied to a con I venti'onal typewriterof the type more completelydi'sclosed in the U) S. Patent: 1,696,906;issued January 1-, 1929 to WI D obson, Only sosmuch of the typewriter isshown herein as is necessary to show the mode of attachment-0'1" themecl lanismof the invention thereto; Referring telig ure 2; thetypewriter base? tail has mountedl theres on a paper carriage llcarrying a; platen; t2; A springidrumzl3 mounted. base: to; con.-nectedzby= ailexihle: tape M to the: carriage H'- to normallyhiasrthe-ncarriage .twthe leftibmlettcr feeding. Also mounted in thebase is an escapement mechanism I5 of conventional type including apinion l6. A carriage carried rack I! mounted in swingable arms I8, onlyone of the arms shown herein, engages the pinion [3 of the escapementmechanism I5 to normally restrain the carriage H from movement.Escapement I5 is released by operation of a type action in theconventional manner to permit movement of the carriage during typing.

The mechanism of the present invention is applied to the above describedconventional typewriter in the form of an attachment. Thecounterbalancing mechanism is easily attached and may, if desired, beremoved when the typewriter is on a stable base. The particularembodiment of the invention chosen for description comprises a bracketl9 fixed to each end of the rear of the typewriter base In, thebrackets, as shown in Figure 1, extending appreciably beyond the sidesof the base I0. A horizontal rail 29 is secured by bolts 2| betweenrearwardly offset portions 22 of brackets 19. A carrier 23 carrying fourrollers 24 is freely movable on rail between the brackets l9. Rollers 24are confined between the body of carrier 23 and ears 25 bent off thecarrier and are mounted on studs 26. The studs 26 pass through carrier23 and rollers 24 and are secured in a counterweight 21, holding thecarrier 23, rollers 24 and weight 21 in a unitary I.

assembly. counterweight 21 has a weight substantially equal to theweight of carriage l 1. Secured by screws 28 to the upper ends of weight21 are a pair of clamps comprising bent strips 29 and movable jaws 30pulled into engagement with strips 29 by screws 3|.

Vertically mounted on an upper forwardly projecting part of each of thebrackets I9 is a rotatable pulley 32 aligned on one side with the clamps29, 36 of the counterweight 21. A loop of flexible tape 33 is passedaround the pulleys 32, one side of the loop being fastened to thecounterweight 2! between the jaws 29, 30 thereof. The other side of theloop of tape 33 is clamped to the rear center of the typewritercarriage. The carriage clamp comprises a block 34 secured to the rear ofthe carriage II and a movable jaw 35 pivoted at its lower end in thecarriage H. The upper end of jaw 35 is moved into clamping engagementwith block 34 by a thumb screw 36 passing through a hole therein andscrewed into a threaded hole in carriage I l. Release of this clamp willfree the carriage of load due to the insertia of the counterweight.

When the carriage l l and counterweight 21 are connected together by theflexible tape 33, it will be seen that they travel in unison but inopposite directions. Hence, if the typewriter base is tilted to eitherside, the component of the carriage weight tending to move the carriageH toward the lower side will be opposed by a force due to thecounterweight 21 tending to move the carriage to the higher side. Asthese two forces are substantially equal and are'opposed, the only forceeffective to move the carriage II will be that due to the spring drum l3which force is independent of the tilt of the typewriter. The carriageII will therefore be moved by spring drum l3 under control of theescapement mechanism IS in the same manner when the typewriter is on atilting base as when the base is in a normal level position.

It will be understood that many variations and changes are possiblewithout departing from the scope of the invention disclosed herein.

What is claimed is:

1. The combination with a typewriter having a frame, a carriage slidableon said frame, a cylindrical rotary platen in said carriage, a spring onsaid frame to urge said carriage in a letter feeding direction and anescapement means operable to release said carriage to the urge of saidspring for resulting letter space movements of said carriage, of meansto render said spring and escapement means effective to letter feed saidcarriage in any position of said frame with respect to the force ofgravity comprising a pair of pair of pulleys attached to the rear ofsaid frame, a continuous belt around said pulleys, means for releasablyattaching said belt to said carriage, a rail on said frame, acounterweight movable thereon in a direction parallel to the directionof motion of said carriage and means connecting said counterweight withsaid belt.

2. The combination of a typewriter having a frame, a paper carriageslidable on said frame, a carriage feed spring on said frame, aconnection from said spring to said carriage, a carriage escapementmeans on said frame normally restraining said carriage against movementbut operable to release said carriage to the urge of said carriage feedspring for single letter space increments of movement, said carriage,carriage feed spring and escapement means so constructed that uponsideways tilting of said frame, the weight of said carriage may overcomethe urging of said carriage feed spring and thus prevent feeding of saidcarriage in response to release of said escapement and means to insurecorrect carriage feed under control of said escapement means, said meanscomprising a counterweight;

means mounting said counterweight on said' frame for movement in adirection parallel to the movement of said carriage, and means on saidframe connecting said carriage and said counterweight for equal movementin opposite directions.

3. In a typewriting machine having a frame, a carriage movable thereon,a spring to urge said carriage in a letter feeding direction and anescapement means for said carriage to intermittently release saidcarriage to the action of said spring, said escapement means normallypreventing movement of said carriage in a letter feeding direction andineffective to oppose a return movement of said carriage, whereby upontilting of said frame said carriage may return to the starting positionor may fail to letter feed in response to an operation of saidescapement means, a guide rail fixed to the rear of said frame andparallel to the direction of motion of said carriage, a counterweightfreely movable thereon, a pulley at each upper rear corner of said frameand flexible means encircling said pulleys and connected on oppositesides to said carriage and said counterweight, at least one of saidconnections being manually releasable.

HERMAN G. HARTMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 875,239 Briggs Dec. 31, 19071,696,906 Dobson Jan. 1, 1929 2,403,269 Eddy July 2, 1946 Certificate ofCorrection Patent No. 2,533,111 December 5, 1950 HERMAN G. HARTMAN It ishereby certified that error appears in the printed specification of theabove numbered patent requiring correction as follows:

Column 4, line 13, strike out the Words of pair;

and that the said Letters Patent should be read as corrected above, sothat the same may conform to the record of the case in the PatentOffice.

Signed and sealed this 20th day of February, A. D. 1951-v THOMAS F.MURPHY,

Assistant Oommz'ssz'oner of Patents.

